(a) What is a sense organ? (b) List four sense organs found in mammals. (c) Describe the processes that will cause a person who has been spinning to feel dizzy (d) State two functions each of the following structures: (i) Cerebellum (ii) Cerebrum (iii) Medulla Oblongata.
Explanation
(a) Sense organ: A sense organ is an organ made up of a group of specialized cells/tissues/receptors , which is able to receive/collect/perceive/detect stimulus and transmit the information/impulse/message to the nervous system. (b) Sense organs in mammals: Nose/olfactory organ; eye; ear; tongue; skin. (c) When a person spins and stops: Endolymph, in the inner ear/semi circular canals continues to move causing sensory hairs/sensory cells to be stimulated. impulses reaching the brain/cerebellum through the auditory nerve show that the person is still spinning the brain interprets the body as still moving - and confusion is imposed on the receptors - sensitive to position - giving the person an impression of dizziness. (d) Functions of: (i) Cerebellum - Receives impulses from the ear; involved in balance and posture; coordinates voluntary muscles. (ii) Cerebrum - Controls voluntary actions/any other correct example; concerned with memory; intelligence. (iii) Medulla Oblongata: Controls involuntary/reflex actions; heartbeat; coughing; sneezing; blinking/any other correct involuntary actions.